Drill-rod coupling.



G. W. MOALLISTER, LLLLLLLLLLLLLL NG.

WlTNESSES I V/,ENTQ R ,BY A

TTORN GEORGE WATSON MoALLISTER, or salt imaxclsco, camronma mum-non coornmo.

Specification of Letters Patent.

Patented Feb. 18,1918.

Original application filed March 8, 1911, Serial No. 613,06; Divided and this application filed hungry ll, 1912. Serial No. 671,998.

To all whom it may concern:

Be it known that I, GEORGE W. MCAL- LISTER, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented a new and useful Drill-Rod Coupling, of which the following is a specification in such full and clear terms as will enable those skilled in the art to construct and use the same.

This invention relates to a drill rod coupling for rotary well drills, and this appli cation for patent. is a division of appl1ca tion for patent filed by me in the United States Patent Office March 8, 1911, Ser. No. 613,064..

An object, of the invention is to produce a drill rod coupling which will be identical with other couplings of its kind and which will be alike at both ends thereof. I

A further object of the invention is to reduce a couplin which will permit the inflow t-herethroug and the outflow therethrough of the water used in the drilling operations.

Another object ofthe invention is to produce means whereby the water passing through the coupling will always have access openings in the drill rods, regardless of whether the longitudinal openings in the couplings and drill rods are exactly alined or not.

In the drawings in which the same numeral of reference is applied to the some portion throughout the several views, Figure 1 is a lan view of the coupling, Fig. 2 is a side e evation thereof, Fig. 3 is a horizontal sectional view on the line 3--3, Fig.

.4, and Fig. 4 is a vertical longitudinal sectional view through the coupling.

The numeral 1 represents the cylindrical outer shell of the coupling, which is threaded at 2 and 3. At the center, the outer shell 18 connected by means of a web 4, said web having two openin s 5 therein anda central opening theret rough. Since the two openings'h are off the center, they are connected at each end by means of a shallow groove 7, said shallow groove being to: the purpose of permittin water flowing through thecoupling to reac similar openings in the'adioining drill rods even though the vertica openings are not exactly alined. The central opening is for the egress from the drill rod and b1ts,'not shown herein, of disintegrated rock particles.

Having thus described my invention what I claim as new and desire to secure by Leters Patent of the UnitedStates, is as folows:

1. In a coupling for drill rods, a shell' having each end internally threaded and having a web adjacent its center, said web having a plurality of openings, one of said 0 enings terminating in a shallow groove in he web at each end of the opening, substantially as described.

2. In a coupling for drill rods, a shell having internal threads at each end thereof and atransverse web immediately adjacent. and between the two series of threads, said web having a central opening and two eccentric openings, the latter two openings being connected at each end thereof by a circumferential groove, substantially as described.

In testimony whereof I have hereunto set my hand this 11th day of January A. D. 1912, in the presence of the two subscribed witnesses. 

